Automatic presser-foot-lifting mechanism



Julie 3, 1930. A, M, WENZEL 1,761,899

AUTOMATIC PRESSER FOOT LIFTING MECHANISM Filed May 22, 1929 3nventor A. M. IVenzel i- Nm-sn tion of the construction shown .in Fig. 1.

Patented; June 3, 1930 r Tus PATE AINNAM. wENzEn or BROOKLYN, NEW YORK 7 AUTOMATIC 'rnnssnn-roorsmrrme MECHANISM Application filed May 22,

This invention relates to sewing machines and more particularly to: automatic presser foot lifting mechanisms therefor, having for its object the provision of a construction simple in parts, moreeflicient in use and leSS costly to manufacture than those heretofore proposed. j j A With these and other objects in view the invention consists in the, novel details of. con- .struction and combinations "of parts as will be more fully disclosed hereinafter; and par- 7 ticularly pointed outinjthe claims. This applicationiconstitutes acontinuation in part of my co-pendingapplication Serial No. 1928, on improvements in sewing machine, 3 r Referring to the accompanying drawings -for ming apart of this specification'in which likenumerals designate like parts in all the 20 views, I

F ig. 1 is a perspective view of the inventionillustrating the tipper'or lifting mechanism in assembly with the needle barhousing;

. Fig. 2 is a rear elevational view of some 25 of the parts shown in Fig. 1; k

Fig. 8 is a sectional view taken as on the .line3i3 of.Fig. l and looking in the directionof the arrows; and] r V Fig. l'is a perspectiveview ofamodifica- This invention contemplates a novel construction which is adapted for makingpossible. stitching of material having various thicknesses. -That is to say, it is desirable to use thesame sewing machine for stitching relatively thin material in single or plural layers and then to immediately change to thick. material without the necessity of using mechanism as a whole may be moved axially .a separate machine. This inventiontherefore .ispdirected to a construction by which this change'can be rapidly made.

1 represents that portion of. the headstock which isintegrally secured'to. the main. body casting 2 of the sewing. machine. At 3 is shown the end portion of the pivoted lever. employed for reciprocating the .needle bar 4:; while-5 indicatesthe presserfoot carried at the base-of the presser foot bar 6 slidable in suitable guides in theheadstock and hav- "ing at its uppe1- ,end an=extending pin :7

1929. Serial No. 365,140.

adapted'to be struck by. a pivoted cam 8 actuated by the handle 9 in the well known manner .bore extending from front to back of the machine and adapted to receive a pin or shaft 14-65 therethrough. On this pin and straddling said lug is mounted a tripper mechanism by means .of which the presser foot is automatically raised as the needle bar is lowered so as to free the material being sewed. This tripper mechanism 1 comprises an inverted if U-shaped frame having one side 15 connected as by the bridge portion 16 in parallel relation with the opposite side 17, the pin 14 passing through both of said sides. The side 15 has an. upward extension 18 provided with a cam edge 19 which is adapted to be struck by a roller 20 carried by the oscillatinglever 3 which reciprocates the needle bar. The

other side 17 is downwardly extended and so has its end angularly bent in a direction toward the headstock to provide a hook or foot 21 whose'upper surface is adapted to contact with the underside of the nut 12 mentioned above.

The distance between the sides 15 and 17 i is made greater than the width of the lug 13 disposed therebetween so that the tripper of the pin 14 as and'when desired. 1 With par- .9

ticular reference to Fig. 3 it will be readily seen that'when the tripper mechanism is in the position shown in full lines the camsurface 19 lies in the same vertical plane with the roller 20 and will be struck thereby as 9 the. needle reciprocating bar 3 is actuated,

butlthat when the tripper. mechanism is Y moved to'the'position indicated by the dotted 7 lines the cam19 will be out of the operating plane of said roller. .Itis also to be observed t that when the mechanism is in the full line position the foot 21 will lie beneath and in axial registry with the nut 12 of the pressure 2 7 foot auxiliary rod 10 but when'the parts are moved to the dotted line position said foot will be out-of engagement therewith.

A flatspring 25jis1rigidly seoured at one end tothe lug 13 with its freeend bearing against a side edge of the bridge -16Iso that,

normally and when not being automatioally operated, the tripper mechanismwillfhave its foot 21 swungdownwardlyaway from' any contacting position with the nut 12. WVhen, however, the roller 20 contacts with the cam surface 19 the tripper mechanism will be 'oscillatedlabout the pin 14 'solthat the foot 21will be movedinto Contact w th and raise thenut 12 with attendantraising, through the well-known intermediate connections ofthe presser tooth froin' the' fee'd "dog'26. 7 1

"It is thusevident that it'isasimple matter for the operator of the maohine tOflHOVG thG triDPerineohanism "at; will in either direction on" ts supporting pin and that when it is'moved toward the front'pf the machine it a will be in position to'be automatically oper- "ated bytheneedle bar'reeiprocating lever to cause an increasedraisingof the presser foot. Byernploying a fiat-spring 25 bearingiagainst the fiat surface of the bridge 16 there ismade possible a free sliding engagement therebetween'at a'll tirnes and further bythe particular construction of the tripper mechanism, there is no'interfe'r'ence w th :the goods being sewed and no Q parts so disposed as :to

obstruct sight ofthe sewing.

] H In Fig.i2 is clearly shown in diagram the results obtained as abovedescribed'. 'Thatgis to say, the foot' 21 of the tripper mechanism is" sl1oW1iin full lines disposedaout of the;

- vertical plane of the presser foot auxiliary dotted lin'e position. The movement: of the foot 21 "is 'olearly shown "to be-osoillatory 7 soribed, th-e modification constituting a change inthe spring "tension pl'aoed upon the de- 'vioe. Stated in other'words,*and as wlllibebar 10 but {is shown-in dotted linesnotzonly in'the plane oisaidrod but supportlng the nut 12 so that thepresser foot 5' israised to its about the pivot' pin l l, Y In F ig: 4 thereis disclosed a slight-modification of the constructionhereinbeforeideseen, the lug 13 is provided with a 5 screw 27 securing one end of' a 'd'ouble action spring 28 which extends upwardly and over into the loop 29 and then has its free end-$3.0 'eX- tending downwardly in substantially 'paraL 1 lel'relation with the member 28 of said spring. The member 30ofthespring is thus adapted to bear against the fiat side-of the yoke .16- the surfaoe of which is'provided with two vertical grooves 81 and 32.1 "When the devi'oe'is in its forward position the, spring will engage the groove 32Jand holdtheldevioe so t will not accidentally slide on the pm 1 1 out of operative'position.

- When, however, the Presser ifoot'lifti'ng l a device is not desired to be 'in lus'e and "is pushed to the rear of the machine, thespring 'will automaticallyrl-eave'thegroove 32 and engage'thet groove 31 'andholdathe devicein I inoperativ'e position. Thesorew 27 maybe of; a q 1 sutlicient lengthto serve, as a set-screw for the pin l l p' eventing aooidental 'disl odg- I ment thereof. s I From the foregoing it will thus be seen that by this invention there is contemplated a tripper:.nreohanisin;.for raising the presser foot ofa sewing machine having n CODlblr so" ,7 natlon a I support including 3- the lug 13 and the pin 1'41} passing 7 therethrough', with a frame slidablymountedion said pin" and straddling thel'ug,-saidframehavingan ext nsion v '17 -adapted to engage oneofthe connections- S5 between the frame and-thebarJO associated with the presser foot 5, the engagement'of the,

foot '21 o'fsaid extension being only permitted wh'ei'rthe frame is at one-limit ofits 1110178- I a ment on the pin'l ianddisengagedtherefrom j V when the'frame'is-slid-toitsother-limit on saidpin. --There is a'lso proyided the se'eond. "extensionofthe fraine=18 whiehis ada ted to 'be'engagedfbyanosoillatingmember 3 o'f f the niaohin'e' 'when the foot- 21 is engagedggfi with the said oonnections '=tothe 'presser "toot whereby the frai'i'ie is-oso il-l ate'd; about the pin l i'andth'e presser footraised. There is provided spring-means -2 5"carri-edby the lug IS f to normally disengage thefoot 2l -froin theg m' resser-foot eonneotionsysaid 'spring means 1 g adapted toapp'ly equal p'ressure'on the frame i F when the frame 'is'substantially contaetin'g with! either side otthe lug l3. By this; construction 7 it willbeseen that 4 the tripper aos mechanism can be slid'at willbythe operator of the Y sewing machine toyoa-use intermittent and automatic raising of the presser foot.

It is obv iou's that those'skilled iin the. art

mayvary the details of oonstruotion asrwell as fil arrangements I of parts without a departing from'the'SPi fitOf-.theinventi'on andkit is therefore" not desired to he limitedto the foregoing I disclosure l except as vmay Sb'e- I de a s ma1'ided b y the claims, 1

presser foot of a sewingvmachinetheeombii nation iota-support including a pin;'a frame I pslidably mountedion said pin; a bar and connections for slidably supporting" said 1;" In a tripper inechanism'forraising the i nections whereby said frame is oscillated about said pin and said presser foot raised. 2,. In a trippermechanism for raising the presser foot of a sewing machine the combination of a support including a lug and a pin passing therethroughra frame slidably mounted on said pin and straddling said lug;

a bar and'connections for slidably support- ',ing said presser foot; an extension of said frame adapted toengage one of said connections when said frame is positioned against one-side of said lug but be disengaged therefrom when. said frame is positioned against the other side of said lug; and a second extension of said frame adapted to be engaged by 'anoscillating member of said machine when said first named extension is engaged with said connections whereby said frame is woscillated about said spin and said presser.

' porting said presser'foot; an extension of against the other side of said 111 said frame. adapted to engage one of said connections when said frame is positioned against one side of said lugbut be disengaged therefrom when said frame is positioned b7 means to normally urge said extension from said connections at all positions of said frame; and a second extension of said frame adapted to be engaged by an oscillating member of said. machine when said first named extension is engaged with said connections whereby said frame is oscillated about said pin and said presser foot raised.

4:. In a tripper mechanism for raising the presser foot of a sewing machine the combination of a support including a lug and a pinwpassing therethrough; a frame slidably mounted on said pin and straddling said lug; a bar and connections for slidably supporting said presser foot; an extension of said frame adapted to engage one of said .connections'when said frame is positioned against one side of said lug but bedisengaged therefrom when said frame is positioned against the other side of said lug; spring 7 means carried by said lug to normally urge said extension from said connections, said a means adapted to apply equal pressure on saidframe when contacting with either side of said lug; and a second extension of said frame adapted to be engaged by an oscillating member of said, machine when said first named extension is enga ed with said connections whereby said frame is oscillated about said pin and said presser foot raised.

5. A tripper device for raising the presser foot of a sewing machine the same comprising a U-shapedframe adapted tobe slidably mounted on a pin carried by a lug on said machine, said pin passing through opposite sides of said frame, an extension of one of said sides provided with a cam surface adapted to be contacted by the end of an oscillating lever of said machine, an extension of the other side of saidframe provided with a projection adapted to cause a lifting of the presser foot of said machine, and a spring carried by said lug and contactingly associated with said frame.

6. A tripper device for raising the presser foot of a sewing machine the same comprising a U-shaped frame mounted on a pin carried by a lug on said machine, said pin passing through opposite sides of said frame and said sides connected by a bridge of a greater length than the width of said lug whereby said frame may be slid at will on said pin to contacting position with either side of said lug, an extension of one of said sides provided with a cam surface adapted to be contacted by the end of an oscillating lever of said machine when said frame is contacting spring carried by said lug and contactingly associated with a surface of said bridge portion of said frame.

In testimony whereof I affix my signature.

ANNA M. WENZEL. 

